Recently, a full view of human genome has been disclosed and post genome researches have been intensively and world widely done aiming for gene therapies and gene diagnosis.
As for the DNA analysis, a sample DNA is analyzed by hybridizing a probe nucleic acid fixed on a microarray substrate with a sample DNA labeled with such as a fluorescence dye and forming a double chain DNA. This method can be done by elongating a nucleic acid labeled with a fluorescence dye by PCR method and by hybridizing on a substrate, and then the fluorescence intensity of the labeled target nucleic acid is measured. Recently, methods such as using a primer having more amino groups than usual or introducing an amino group to DNA have been used.
A fluorescence dye is widely used for labeling. High fluorescence intensity, emission even under dry conditions (solid conditions), water solubility, and the like are required for the fluorescence dye. As the fluorescence dye, for example, Cy3 and Cy5 are used (see, e.g., Science 283, 1 Jan. 1999, pp. 83-87).